High speed packaging method and machine



Nov. 15, 19.60 J. D'.'coN-n HIGH SPEED PACKAGING METHOD AND MACHINE Filed April a, 195e 8 Sheets-Sheet 1' Nov. 15, 1960 .1. D. CONTI HIGH SPEED PACKAGING METHOD AND MACHINE Filed April e, 195B 8 Sheets-Sheet 2 Nov. 15, 1960 J. D; coN'rl HIGH sPEED PACKAGING METHOD AND MACHINE Filed April s. 195s 8 Sheets-Sheet 3 Nov. 15, 1960 J. D. coN-rl HIGH SPEED PACKAGING METHOD AND MACHINE Filed April 8. 195e 8 Sheets-Sheet 4 Nov. 15, 1960 J. D. CONTI HIGH SPEED PACKAGING METHOD AND MAcHmE Filed April e, 1958 8 Sheets-Sheet 5 Nav. 15, 1960 J. D. coN-vrl HIGH SPEED PACKAGING METHOD AND MACHINE Filed April 8. 1958 8 shets-sheet e Sal Ffm

Ell

INI

Nov. 15, 1960 J. D. coN-rl HIGH SPEED PACKAGING METHOD AND MACHINE Filed April 8, 1958 8 Sheets-Sheet '7 w NGN f XN Nov. 15, 1960 1.13. coN'rl HIGH SPEED PACKAGING METHOD AND MACHINE Filed April e, 195e 8 Sheets-Sheet 8 OWN HIGH SPEED PACKAGING METHOD AND MACHINE John D. Conti, Elkins Park, Pa., assignor to American Viscose Corporation, Philadelphia, Pa., a corporation of Delaware Filed Apr. 8, 1958, Ser. No. 727,073

28 Claims. (Cl. 53-28) This invention relates to packaging machinery and more. particularly to continuous high speed wrapping and sealing apparatus `and method. The present invention is primarily designed to individually enclose articles such as lettuce, cabbage,` etc. in a casing of heat sealable material, for example, cellophane.

With the increasing demand for the individual wrapping of various products, and particularly food items sold on produce counters of self-service stores, there has been a corresponding need for automatic high speed machinery capable of enclosing objects of relatively uniform dimensions in sheet material, such as cellophane, `at speeds better than two articles per second. Such speeds can be achieved where the articles are continuously fed to and through the packaging machine without interrupting their travel so that all operations are performed on the iarticles andthe wrapping material while they `are actually traveling through the machine. It is also desirable to provide a generally straight-line movement for the articles to be wrapped, with the elimination of most all reciprocating parts beingy a factor in overcoming the disadvantages of the relatively slow and cumbersome wrapping machines of the prior art. Accordingly, a primary object of this invention is to provide a new or generally improved and more. satisfactory packaging machine and method.

Another object is the provision of an improved high speed packaging apparatus in which the articles to be wrapped and the wrapping material are continuously advanced, preferably along a generally straight-line path.

Stillanother object is to provide in a high speed wrapping machine, means for shaping -a sheet rwrapping material into a trough formation and maintaining control of the-trough-shaped wrapping material throughout an article loading station.

A further object is the provision of `a packaging appa.- ratus of the type described having Van article loading station in which articles are disposed within Va continuously advancing trough-shaped wrapping material and are supportedv for movement therewith by means positioned outwardly of the wrapping material itself.

A still further object is to provide an Iapparatus of the typev described wherein a series of individual spaced articles are positioned within a trough-shaped wrapping material which is sealed longitudinally and at selected intervals transversely to provide a closed tube sealed lat positions between the articles themselves.

A still further object is to provide a packaging apparatus having means for bunching, sealing and severing a closed tube of wrapping material between larticles positioned therein.

A still further object is the provision of a packaging machine having means for bunching an ladvancing closed tube of wrapping material along different planes and between articles disposed within the tube, and then sealing and severing the hunched tube to provide individual packages.

These and other objects, features, and advantages will States Patent Op Patented Nov. 15, 196Q ICC become apparent from the following description ofthe invention and the drawing relating thereto in which:

Figure 1 is a side view of a portion of the machine of the present invention showing apparatus for feeding and shaping a wrapping material, along with a portion of an article loading station;

Figure 2 is a continuation of the structure shown in Figure 1, illustrating apparatus for sealing a Wrapping material to provide a closed tube around a series of spaced articles;

Figure 3 is a top view of the structure shown in Figure l;

Figure 4 is a top view of the structure shown in Figure 2;

Figure 5 is an enlarged side view of the sealing rolls shown in Figure 2;

Figure 6 is a continuation of Figure 2 showing mechanism for bunching, sealing, and cutting the tube-shaped wrapper between the articles disposed therein;

Figure 7 is a view of the left end of the structure shown in Figure 6, with portions thereof being broken away;

Figure 8 is an enlarged side view of a portion of the structure shown in Figure 6, more clearly illustrating the tube-shaped wrapper movement into the bunching mechanism;

Figure `9 is a fragmentary top view of the structure shown in Figure 6;

Figure l0 is a topA view of one of the lower bunching and sealing elements;

Figure 1l is a transverse vertical section taken along the. line 11--11 of Figure l0;

Y Figure 12 is an end view of one of the upper sealing and severing elements, with portions thereof broken aways,

Figurey 13 is a; fragmentary perspective view showing the relative positions of the tube-shaped wrapper and sealing elements prior to the actuation of the side gathering elements;

FigureV 14- is a -view similar to Figure 13 illustrating theparts after the side gathering elements have been actuated;

Figure l5 isa view similar to Figures 13 and -14 show. ingthe parts after the wrapper bunching, sealing and cutting operations have been completed;

Figure 16 is a top View of the completely wrapped sealedarticle.

In general;1 with the apparatus of the present invention, a continuous web of wrapping material, such as cellophane coated with a heat sealable material, is drawnl from a supply roll and formed into a U-shaped article receiving trough. Gripping elements engage with the longitudinal edges of the trough and carry the same toward a sealing station, along with articles placed in. the trough at spaced intervals. A conveyor is positioned beneath the path of the trough and is provided withA pinsV or lugs which support the articles during/their travelV without altering their desiredspaced relationship. As the trough approaches the sealing station, the gripping elements are released and the longitudinal edges aresealed between a pair of cooperating rolls toY provide a* closed tube of wrapping material about the spaced articles.

Gathering of the by cooperating bunching elements. Sealing and severing of the tube of wrapping material is effected while the tube is maintained in its bunched relationship. An important feature of'the invention resides in the fact that all of the above operations are carried out automatically and in a desired sequence as the articles and wrapping material are continuously advanced. Therefore, all of the moving parts of the machine are driven in timed relationship from a single motor which provides an effective control for either increasing or decreasing the operating wrapping rate.

Referring now more particularly to Figures l-S of the drawing, `the preferred embodiment of the invention inof the wrapipng material, yet may be readily moved to cludes a table 20 having standards 22 and a pair of arms 24, at one end, on which is mounted a supply 26 of wrapping material W. Any suitable heat and pressure scalable material, such as coated cellophane, may be used as a wrapping material. The wrapping material W is drawn from the supply 26 and passed over a roll 28 carried by brackets 30 which are fixed to a platform 32. Bolts 34 and nuts 36, along with elongated slots 38 formed in the platform 32, see Figure 3, permit the platform to be adjusted relative to the table 20, as desired. A forming device 40 shapes the wrapping material W into a U-shaped trough and includes a generally triangular plate 42 carried by the brackets 30, and a pair of dellector arms 44 secured at 46 to brackets 48 extending vertically from the platform 32.

The longitudinal edges of the wrapping material W are directed by the arms 44 between pairs of guide pins or rollers 50, and are then engaged at spaced intervals by spring loaded gripping elements 52 secured to conveyor chains 54. The rollers 50 are carried by elongated side plates 56 which in turn are supported by members 58 and 60 fixed to bearing blocks 62 and the table 20. Sprockets 64 support the chains 54 at one end and are carried by stub shafts 66 which project through the side plates 56. Cams 68, see Figure 3, are also supported by the shafts 66 and serve to open the gripping elements at the forward end of their travel so that they are individually fed over each upper edge of the wrapping material.

A pair of cooperating rollers 70 and 72 advance the wrapping material and assist in forming and maintaining the same in its desired U-shape configuration. The roller 70 is positioned within the trough-shaped wrapping material and has a shaft 74 supported by arms 76 which are swngably mounted on a shaft 78 extending between the brackets 48. A shaft 80 carries the roller 72 below the wrapping material trough and is journalled between plates 82 fixed to the platform 32. As more fully described hereafter, rotary movement is applied to the roller 72 and is transmitted through chain 84 and suitable sprockets to a shaft 86 extending between brackets 48. By means of sprockets fixed to the shafts 86 and 78, land cooperating chains 88 and 90, a driving force is applied to a sprocket 92 fixed to the shaft 74 intermediate segments of the roller 70. Preferably, at least one of the rollers 70 and 72 is provided with a friction surface, such as rubber to insure good contact with the wrapping material.

Cooperating with the rollers 70 and 72 in advancing the wrapping material W are roller assemblies 94, each being similar in construction and including a pair of rollers 96 and 98 between which the edges of the wrapping material travel. The rollers 96 are supported from the blocks 62 by brackets 100 and are operatively connected by meshing bevel gears to shafts 102 which extend through the side plates 56. Rotary movement is transmitted from the shaft 78 to the shafts 102 by chains 103 trained over suitable sprockets. Rollers 98, on the other hand, are rotatable carried by arms 104 which are hinged at 105 to the side plates 56. Springs, not shown, urge the arms 104 toward the adjacent driving rollers 96, and thusthe rollers 98 are driven by the movement facilitate easy lacing of the machine.

As trough-shaped wrapping material W is advanced by the movably mounted gripping elements 52, the articles to be wrapped, indicated at A, are positioned therein at spaced intervals and are supported by a conveyor assembly 106 disposed beneath the path of the wrapping material. This assembly 106 includes a pair of spaced chains 108 and 110 having article supporting lugs or pins 112, and an endless belt 114. The chains 108 and 110 are supported at one end by sprockets 116 carried on a shaft 118 which is journalled in the blocks 62, and at their opposite ends by sprockets 120 fixed to a shaft 122 extending between a pair of beams 124. The beams 124 are swngably mounted at one end to the shaft 118 and are adapted to be adjusted in a vertical direction at their opposite end by a bolt 126 threadedly passing through the table 20 and having a lock nut 128. It will be evident that adjustment of the beams 124 relative to the table facilitates adequate support of the articles A by the assembly 106 regardless of the depth of the wrapper trough W. The conveyor assembly belt 114 passes over rolls 130 and 132 carried by the shafts 118 and 122, and, as shown in Figure 2 extends over a roll 134 journalled between arms 136 which project outwardly from the beams 124. The chains 108 and 110 are preferably supported along Itheir travel by suitable guides fixed to members 58. It will be apparent that the pins 112 serve to support and correctly position the articles A within the trough W, and if desired, may be replaced by platforms of a shape best suited for the artciles being wrapped. To prevent the wrapper trough W from being displaced laterally from its desired path,

a wrapper support cradle is provided including a series of elongated bars 138 positioned along opposite sides of the trough and supported by cross bars 140 fixed to the brackets 58 and 60.

At the end of their travel from the forming mechanism of the machine, the gripper chains 54 pass over sprockets 142 and are directed into converging relationship, see Figure 4, to dispose the longitudinal edges of the wrapper trough W in side-by-side position for movement between a pair of sealing rolls 144, which are best seen in Figure S. 'Ihe sprockets 142 are fixed to countershafts 146 carried by a framework 148. Cams 150, also supported by the framework 148, engage with the gripping elements `52 and serve to release the same from the edges of the wrapping material as the chains 54 start their return travel.

The sealing units or rolls 144 are mounted between bars 152 carried by the framework 148, with at least one of the rolls 144 being urged into its desired operating position as by a spring 154 and an adjusting screw 156. Ihis resilient mounting the sealing rolls 144 will of course permit obstructions to pass therebetween without damaging the machine, and in addition facilitates easy lacing operations. Heating elements (not shown) are mounted in the rolls 144 and are energized through rings 158 and contacts 160, the latter of which are connected to a suitable electrical source. A rotary movement is applied to one of the rolls 144 by meshing bevel gears 162 and 164 and is transmitted to the adjacent roll 144 by meshing pinion gears 166. A shaft 168 carries the gear 162 and is in turn supported by arms 170 fixed to the framework 148.

The sealing units or rolls 144, as best seen in Figures 2 and 5, each include a substantially circular portion 172 and an intermittent or fragmentary arcuate portion 174. The portions 174 are each generally similar to an ungula of a right circular cylinder and are formed with curved side edges 176 which are disposed in converging relationship and provide the ends of the arcuate portions remote from the circular portions 172 with peripheral surfaces of reduced length. As more fully described hereafter, the rotation of the rolls 144 is coordinated with theadvancingmovem'ent of the wrapperW,rv aridtheY rolls themselves are positioned so that the arcuatelv portions 174 move into directly opposing relationship as a portion of the wrapper tube r between spaced articles travels therebetween. Thus, with sealing rolls having a construction as described above, the circular portions 172 serve to unite the longitudinal edges of the trough-shaped wrapper to form a closed tube around the articles placed therein at spaced intervals, while the arcuate portions 174 transversely seal the tube between the articles themselves. In view of the configuration of the arcuate portions 174, seals 178 between the articles will resemble, in general, inverted triangles having curved walls corresponding to the curved side edges 176 of the arcuate portions.v The side edges 176 conform, in general, to the shape of the articles A being wrapped and thus the articles are enveloped by a snug fitting cover.

As best shown in Figure 5. the surfaces of the circular portions 172 of the sealing rolls are provided with mating corrugations 180 and 182, while the arcuate portions 174 are formed with mating corrugations 184 and 186, at spaced apart locations. Sealing the opposite surfaces of the wrapping material while simultaneously corrugating the same will insure the formation of a strong seal. More important, corrugating the wrapping material while sealing prevents the tube from spreading outwardly in vertical directions and permits proper transverse sealing without distorting or tearing the wrapper itself. It will be further noted that the vertically spaced seals extending transversely of the tube, do not impair the flexibility of the tube at these areas, and facilitate the further gathering or bunching of the transverse seals in a vertical direction, as more fully described hereafter. It will of course be understood that the configuration, size and sealing surfaces of the sealing rolls may be modied to provide transverse seals of any desired shape which are best suited for the articles being packaged.

Movement of the various parts of the machine in timed relationship is effected by a single motor (not shown) having a main drive chain 188 trained over a sprocket 190 fixed to a shaft 192. Sprockets 194, fixed to shaft 192, and chains 196 drive sprockets 198 on the countershafts 146 and thus both series of gripping elements 52 are moved in unison. Meshing gears 200 on shafts 192 and 202 both of which are journalled between the beams 124, serve to transmit movement to chains 204 and 206 through sprockets 208 and 210 fixed to the shaft 202. The chain 204 in turn drives a sprocket 212 on the shaft 168 for turning the sealing rolls 144, while the chain 206 drives a sprocket 214 on `the shaft 122 for moving the article support assembly 106. The movementy of Vthe assembly 106 is relied upon for turning the shaft 80, see Figures 1 and 3, through the chain 216 and sprockets 218 and 220 fixed to the shafts 80 and 118, respectively. From the drive system described, it will be apparent that any change in the feed of the shaft 192 automatically controls the speed of the gripping element and article supporting chains, the sealing rolls, and the trough forming and advancing mechanism.

With reference particularly to Figures 6-9, the bunching, sealing, and severing arrangement of the present invention includes upper and lower conveyor assembliesy 222 and 224, respectively, which together define a path for the article enclosing tube of wrapping material W. The upper conveyor assembly 222 is mounted on shafts 226 and 228 journalled in side frame members 230 and 232, and comprises a pair of chains 234l and 236 trained over sprockets 238 and 240. The lower conveyor assembly 224 is mounted on similar shafts 242 and 244, likewise journaled in side frame members 230 and 232, and also comprises a pair of chains 246 and 248 passing over sprockets 250 and 252.

A series of pressure sealing and severing elements 254 are carried at spaced intervals by the chains 234 andf236 and arey aligned with heat sealing elements 256 supportedY by thechains 24'6 and 248.v An endless beitlzssfispa'ssa about a main drive pulley 260, driven pulleys 262-and1 264, fixed to the shafts`244 and 228, respectively,'and"an idler roll 266 to drive the upper and lower conveyor as;y semblies in unison along directions as indicated by: the* arrows in Figure -6. A shaft 268, for the pulley 260,; and the idler roll 266 are both rotatably mounted on the'v side frame member 230. The upper and lower conveyor assemblies are operatively connected to the loading station'V mechanism and controlled from the single power source (not shown) by the main drive chain 118 which is trained over a sprocket 270 xed to the shaft 2684.

The pressure sealing and severing elements 254, asV

best'seen in Figures 7 and l2, each include a body member 272 which is connected by links 274 to the chains 234 and 236. A pair of spaced guides 276 project from the face of the body member 272 and slidably receive a pair of spaced blades or jaws 278 which are resiliently urged against the body member 272 by a series of tension springs 280. The faces of the jaws 278 may he corrugated or grooved for all or part of their length, if desired. A housing 282, fixed to the main body 272, slidably supports a cutting blade or knife 284 which is selectively reciprocated, as hereafter described, between the jaws 278. Sealing elements 256 of the lower conveyor assembly are generally similar to the elements 254 described above, except for the absence of the cutting knife 284. While not illustrated on the drawing, it will be `understood that jaws 286 and body member 288 of the lowersealing elements 256 may be resiliently connected in much the same manner as in the elements 254.

The sealing elements 254 and 256 on each ofthe conveyor assemblies 222 and 224 are timed to travel along l veyor assemblies 222 and 224, as seen in Figure 8, thei` articles A are individually engaged by a pair of arms 290 and 292 carried by each of the sealing elements 256. The arms 290 and'292, as shown in' Figure l0, are pivoted at' 294 to the body member 288 and are interconnected by a link 296, with a tension spring 298 extending between the arm 290 and the link 296.' As the sealing elements 256 move into initial engagement with the wrapper tube'W, j

the arms 290 4and 292 engage with the trailingportion of an enclosed article A and are gradually spread apart, against theaction of the spring 298, ,into embracing positions on opposite sides of the article. In this manner, the'farticles are advanced into the path between the asV` semblies 222 andV 224 and eliminate any tendency for the articles to slide rearwardly within the enclosing tube W. Stops may be provided on the body members 288 for limiting the spreading of the arms 290 and 292. It will be noted that free ends of the arms 290 and 292 are beveled at 300 to prevent damage to the wrapper W and the enclosed articles. Once the articles enter the path between the upper and lower conveyors, they are each sup-v ported by platforms or article rests 302, best seen n Figure 11, which are hingedly secured at 304 tothe sealing elements 256. The rests 302 are each urged and maintained in a horizontal position beneath the articles by a roller 306 carried by the rest and engaging with af track 308, supported from the side frame members 230 and 232 by suitable means, not shown.

The sealing elements 254 are each supported along the-path of the tubular wrapper W, as shown in Figure 7,

by a series of rollers 310 which are connected to the body frame members 230 and 232 by any Vsuitable means, such' as cross-bars 326.

256 register with each other midway between the enclosed article and in this manner gather or squeeze the Wrapper tube W along a vertical direction. It will be noted, however, that the sealing elements 254 and 256 do not completely press the wrapper together during the initial stage of their travel but merely serve to inaugurate a bunching of the wrapper, as shown in Figures 6 and 13. Final and complete bunching of the wrapper tube along a vertical plane is effected by a pair of rails 328, see Figure 7, against which engage rollers 330 carried at the ends of each pair of upper sealing jaws 278. The rails 328 are supported from the side ame members 230 and 232 and are each formed with a lower cam surface 331, see Figure 6, which urges the rollers 330 and the jaws 278 downwardly against the resilient action of the jaw supporting spring 280. In the event the jaws 286 on the lower sealing elements 256 are also resiliently mounted on their body members 288, rails corresponding to the rails 328 are provided for urging the jaws 286 upwardly simultaneously with the downward movement of the jaws 278.

Between the preliminary and final bunching of the Wrapper tube W in a vertical direction, gathering elements 332 engage with the tube between the articles positioned therein and squeeze the same along a transverse or horizontal plane. A cooperating pair of gathering elements 332 is positioned in alignment with each of the lower sealing elements 256, as shown in Figures 7 and l0. The gathering elements 332 each include a base member 334, a pair of guide rods 336 supported by the base member 334, a block or carriage 338 slidably mounted on the guide rods 336, and a series of spaced gathering plates or lingers 340, 342, and 344 fixed at one end to the slide block 338. The base members 334 of each pair of cooperating gathering elements are secured to the adjacent ends of the sealing element 256 positioned therebetween, and are provided at their opposite ends with U-shaped brackets 346. As shown in Figure 7, the chains 246 and 248 of the lower conveyor assembly 224 are pivotally connected at 348 to arm 350 of each of the brackets 346 for advancing the lower sealing elements 256 and the gathering elements 332 along the desired path. The outermost ends of the gathering elements 332 are supported by rollers 352 which are carried by arms 354 of the brackets 346 and ride along tracks 356 fixed to the side frame members 230 and 232.

Movement of the transverse gathering fingers 340, 342, and 344 between their retracted and projected positions, as shown in Figure 9, is controlled by a flat cam plate 358 mounted above each of the lower conveyor chains 246 and 248 by brackets 360 connected to the side frame members 230 and 232. A cam roller 362 is carried bv each of the slide blocks 338 and rides along a slot 364 formed in the lower surface of the cam plate 358. As the cooperating cam rollers 362 and cam plate slots 364 urge opposing slide blocks 338 toward each other, the gathering fingers 340, 342, and 344 carried thereby bunch the wrapper tube W transversely until opposing fingers are in abutting relationship. The gathering fingers are each provided with a V-notch 366 on its leading edge to assist in bunching the wrapper tube W to the exact desired width. It will be noted from Figures 9, 10 and 14, that the gathering fingers 342 slide between the jaws 278 and 286 of the upper and lower sealing elements 254 and 256, while the fingers 340 and 344 move along the opposite sides thereof. Thus, with this arrangement, the sealing jaws may be pressed together, as heretofore described, before the gathering fingers are retracted.

Sealing of the wrapper tube W at the completely bunched areas is accomplished by the sealing jaws 278 and 286, which carry and are heated bv thermostatically controlled electrical units, not shown. Electrical current for the heating units is supplied, as shown in Figure 7,

through contacts 368 and 370, secured to each of then sealing elements 254 and 256, respectively, and slidably engaging with electrical contact plates 372 and 374. The contact plates 372 and 374 are suitably insulated and supported by the side frame members 230 and 232.-

It will be noted, from Figure 6, that once the cooperating pairs of sealing jaws 278 and 286 are urged into their final sealing position, they are maintained in this` position for the remainder of their travel with the wrapper tube W. With this arrangement, a strong heat seal is provided between the articles and the bunched areas of tube are held fixed as the wrapper is severed by the blades 284. Reciprocation of the blades` 284 into operative and inoperative positions is accomplished, as shown in Figure l5, by rollers 376 which are carried by each of the blades 284 and engage with pairs of cam members 380 and 382. The pairs of cam members 380 and 382 are supported from the side frame members and include inclined surfaces 384 and 386, respectively. As the rollers 376 on each of the upper sealing elements 254 ride along the inclined surfaces 384 on the cam members 380, the blade 284 is projected between the jaws 278 to sever the wrapper tube at the hunched and sealed area to provide an individual package as illustrated in Figure 16. Retraction of the blade 284 is accomplished by the movement of the rollers 376 upwardly along the inclined surfaces 386 of the cam members 382.

In operation, the sheet of wrapping material, which may be cellophane, paper, glassine or any other satisfactory material, is drawn at a controlled rate from the supply roll 26 and formed into a continuously moving and supported trough by the nip rollers 70 and 72, the forming members 42 and 44 and the grippers 52. The trough is formed directly over a conveyor which moves at the same rate and provides support as well as proper spacing for articles deposited in the trough either manually or automatically. The gripper chains then converge and release the edges of the wrapping material to deliver the juxtaposed edges between a suitable sealing mechanism. The regularly spaced articles are then formed orV encased in a longitudinally sealed tube which is delivered to a station formed by heat-sealing bunching members traveling on conveyor chains which simultaneously gather and bunch the wrapping material midway between the articles to a predetermined and control dimension. Heat and/or pressure sealing is then applied while the conveyors are moving at the same constant rate whereupon the sealed material is severed in the middle of each joint.

The wrapping machine, constructed in accordance with the present invention, is relatively simple and capable of being operated at extremely high speeds to provide the wrapped articles shown in Figure 16. Each wrapper has a longitudinal seal and two end seals which provide a Very effective wrapper. A feature of this wrapper resides in the transverse seals 178 which follow the contour of the articles. In the packaging of certain types of produce, it has been found undesirable to wrap the articles without providing for some air space. Furthermore, the housewife can cut one end of the wrapper and use the severed wrapper as a bag for storing the lettuce or other food product in the refrigerator until fully consumed. The apparatus has been carefully designed to eliminate intermittent and reciprocating operation which would retard or interrupt continuous movement of the articles and wrapping material through the machine. Consequently, it has been found that the wrapping machine may be 0perated at speeds on the order of `200 articles per minute. Such speeds in a wrapping machine of this type have heretofore been considered impossible.

While the present machine has been designed especially to wrap head lettuce, the same machine can be used with little or no modification to Wrap similar articles of produce such as cabbage, egg plant, grapefruit, oranges, squash, etc. Obviously, the machine of the present invention is in no way limited to wrapping food products` 9 since it could also be used either with or without modification for any generally spherical or symmetrical object Within the size limits of the machine.

It is seen from the above description that the objects of the invention are well fulfilled by the method and structure described. The description is intended to be illustrative only and it is to be understood that changes and variations may be made without departing from the spirit and scope of the invention as defined by the appended claims.

I claim:

1. In packaging apparatus, means for supporting a supply of wrapping material, means for shaping and feeding the wrapping material to form an article receiving trough, means for engaging with and advancing the trough along a path, means positioned valong the path of the trough for supporting articles placed` .into the trough at spaced intervals, means for sealing the edges of the trough to form a tube around articles placed therein, means for gathering the tube between articles therein, means in alignment and operative concomitantly with said gathering means for bunching and sealing the tube along a plane extending at an angle to said gathering means, and means for severing the hunched and sealed tube between the articles.

2. An apparatus as defined in claim 1 wherein said means for engaging with and advancing the trough along a path includes series of laterally spaced elements for gripping the edges of the trough, and means for moving the gripping elements along the path of the trough.

3. A packaging apparatus including a platform, means for supporting a supply of wrapping material at one end yof said platform, means for forming the wrapping material into an article receiving trough, a plurality of gripping elements for engaging with the trough, said gripping elements being movably mounted for advancing the trough along a path, means for sealing the longitudinal edges of the trough to form a tube around articles placed therein at spaced intervals, and means for guiding the gripping elements into converging relationship as they approach the end of said path to position the longitudinal edges of the trough in side-by-side relationship as they move into said sealing means.

4. Apparatus as defined in claim 3 further including means for bunching and sealing portions of the tube between articles therein, and means for severing the tube at the hunched and sealed portions.

5. A packaging apparatus including a platform, means for support-ing a supply of Wrapping material adjacent one en'clof said platform, means for forming the wrapping material into an article receiving trough, a plurality of movably mounted gripping elements for engaging with and advancing the trough along a path, means for opening said gripping elements adjacent the forming means. for securing the same to the article receiving trough, means for sealing the longitudinal edges of the trough to form a tube around articles placed therein at spaced intervals, means for guiding the gripping elements into converging relationship as they approach the end of said path to position the longitudinal edges of the trough in side-by-side relationship, and meansv adjacent to said guiding means for releasing the gripping elements from the trough as the trough moves into said sealing means.

6. An apparatus as defined in claim 5 wherein said sealing means includes portions for sealing the tube transversely between the spaced' articles concomitantly withl the sealing of the trough longitudinal edges.

7,. In packaging apparatus, means for supporting Ia supply of wrapping material, means for shaping and feeding the wrapping material to form an article receiving trough, means for advancing the trough, means for sealing the longitudinal edges of the trough to form a tube around articles. placed therein at spaced intervals, said sealing(-` means` including portions, for sealing the tube transversely between the spaced articles ccneomitantly 10 with theV tube formation, meansI for bunching the tube at said transversely sealed areas, and. means for sealing the tube Vat said bunched portions.

8. A continuous packaging machine including a platform, means for supporting a supply of wrapping material adjacent one end of said platform, means for forming the wrapping material into an article receiving trough, a roller positioned outwardly of the trough yand adjacent said forming means, a cooperating pressure roller in the trough, at least lone of said rollers being driven for drawing wrapping material from the supply and through said forming means, a plurality of gripping elements, means for moving said gripping elements 'along a path contiguous to the edges of the trough, means for longitudinally sealing the edges of the trough around 'articles placed therein at spaced intervals, means adjacent to said forming means for opening said gripping elements for securely anchoring the edges of the wrapping material thereto, means for guiding the trough edges into the gripping elements, means disposed adjacent to and movable lwith the trough for supporting Iarticles placedtherein at spaced intervals, means for converging opposing gripping elements to position the longitudinal edges of the trough in side-by-side relationship as the trough approaches said sealing means, means for opening the grippers as the longitudinal edges move into said sealing means, means for bunching the tube between spaced articles therein, means for sealing the tube at ythe hunched portions, and means for severing the tube at the hunched and sealed portions.

9. In a` packaging machine, a pair of substantially parallel spaced members defining a path, means for moving said members along said path at substantially the same speed, bunching elements carried by said members atk spaced intervals along the length thereof, said bunching elements assuming confronting positions las said members are moved along said path, gathering elements positioned on opposite sides of said members, and means for selectively projecting and retracting said gathering elements between said members and into alignment with said bunching elements.

10. In a packaging machine, means for gathering a tube-shaped wrapper between articles disposed therein at spaced intervals including a pair of substantially parallel spaced members defining av path for' the tube-shaped wrapper, means for moving said `members along said path at substantially the same speed, bunching elements carried by said members at spaced intervals thereof, said bunching elements assuming opposing positions between articles in the tube-shaped wrapper as said members are moved along said path whereby the tube-like wrapper is gathered along one plane, gathering elements carried by one of said members, and means for selectively pro,- ject-ing and retracting said gathering elements between said members and in alignment with said bunching elements for gathering the tube-like wrapper between the articles therein along a secondplane.

l1. An apparatus as defined in` claim l0 further including means for engaging with each of the enclosed articles and urging the same into the path between said members.

12. A continuous packaging machine for gathering and sealing a tube-shaped wrapper between articles disposed therein at spaced intervals comprising a platform, a pair of spaced conveyors positioned in substantially parallel relationship and defining a path for the tube- .shaped wrapper, means for moving said conveyors in elementsiixed thereto, and means for actuatingthe 'i i gathering elements between a retracted position on their j conveyor and an extended position between saidsealing elements to gather the tube-.shaped wrapper in a` trans-l verse direction. L

13. A machine as defined in claim 12 wherein said sealing elements include split parallel bars and said gathering elements comprise a plurality of blades movable along opposite sides and between the bars of said sealing elements as they are actuated between their retracted and extended positions.

14. A machine as defined in claim 12 wherein said means for transversely actuating said gathering elements includes a plate cam and further including means for heating said sealing elements.

15. A machine as defined in claim 12 further including rollers on said sealing elements, a track on which said rollers ride as said conveyors are moved, and means associated with at least one of said tracks for urging the sealing elements into pressure sealing relationship with the tube-shaped wrapper after said conveyors have moved along a portion of their path and said gathering elements have been moved into an extended position.

16. A machine as defined in claim 12 further including a reciprocable blade on each of the sealing elements carried by one of said conveyors and means for individually reciprocating said blades to sever the tube-shaped wrapper at the gathered and sealed areas.

17. A packaging apparatus including means for supporting a supply of wrapping material, means for shaping the wrapping material to form a trough, means for sealing the edges of the trough to form a tube around articles placed in the trough at spaced intervals, a pair of substantially parallel members detining a path for the tube, means for moving said members in unison along said path, opposed heated bunchng elements carried by said members at spaced intervals for engaging with the tube between the articles therein, gathering elements carried by one of said members, in alignment with said bunchng elements, means for actuating said gathering elements between a retracted and extended position for gathering the tube yalong a plane extending at an angle to said bunchng elements, and means for severing the tube at the bunched portions.

18. An apparatus as defined in claim 17 further including means for engaging with each of the enclosed articles and urging the same into the path between said members.

19. An apparatus as defined in claim 17 wherein said iirst-mentioned sealing means includes means for sealing the tube transversely between the articles positioned therein concomitantly as the longitudinal edges of the trough are sealed.

20. A packaging apparatus including a platform, means for supporting a supply of wrapping material at one end of said platform, means for forming the wrapping material into an article receiving trough, a plurality of gripping elements for engaging with the longitudinal edges of the trough, means for moving said gripping elements along a path, means for opening said gripping elements adjacent -the forming means for securing the same to the article receiving trough, means for sealing the longitudinal edges of the trough to form a tube around articles placed therein at spaced intervals, means for guiding the gripping elements into converging relationship as they approach said sealing means, means adjacent to said guiding means for releasing the gripping elements from the trough as the trough moves into said sealing means, a pair of spaced conveyors positioned in substantially parallel relationship and dening a path for the tube, means for moving the conveyors in unison, a plurality of heated bunchng elements carried by said conveyors, transverse gathering elements carried by one of said conveyors on opposite sides of the heated bunchng elements, means for transversely actuating the gathering elements etween retracted and extended positions for gathering the tube between the articles therein, said heated bunching elements cooperating to bunch and seal the tube between the articles at substantially right angles to the gathering elements, and means for severing the tube at the bunched and sealed areas.

21. The method of packaging articles in a continuous web of wrapping material comprising drawing wrapping material from a supply, shaping said wrapping material into a generally horizontal trough formation, placing articles to be wrapped within said trough at spaced intervals, longitudinally sealing the edges of the trough around the articles to form a tube while concomitantly sealing transverse portions of the tube between articles disposed therein, and bunchng and sealing the tube at said transverse portions.

22. A method of packaging articles including the steps of drawing wrapping material from a supply, forming said wrapping material into a horizontal trough, gripping the edges of the trough, placing articles to be wrapped in said trough at predetermined spaced points, sealing the longitudinal edges of the trough together to form a tube about the articles placed in the trough, bunchng the tube between the articles in one plane, concomitantly bunchng the tube between the articles at an angle to said one plane, sealing the tube at said bunched portions, and cutting the tube at said bunched and sealed portions.

23. A method of packaging articles including the steps of drawing wrapping material from a supply, forming said wrapping material into a horizontal trough, placing articles to be wrapped in said trough at predetermined spaced points, converging the edges of the trough, longitudinally sealing the edges of the trough around the articles to form a tube, concomitantly bunchng the tube between the articles in diterent planes, sealing the tube at said bunched portions, and cutting the tube at said bunched and sealed portions.

24. The method of packaging articles in a continuous web of wrapping material which comprises continuously drawing wrapping material from a supply, forming said wrapping material into a trough, placing the articles to be wrapped in the trough at predetermined spaced points, longitudinally sealing the edges of the trough around the articles to form a tube, partially bunchng the tube in one plane between the articles therein, bunchng the tube to a predetermined dimension between the articles along a plane extending at an angle to said one plane, pressing the tube at said bunched portions along said one plane to seal the tube, and cutting the tube at said seals.

25. The method of packagng articles in a continuous web of wrapping material which comprises continuously drawing wrapping material from a supply, forming said wrapping material into a horizontal trough, placing articles to be wrapped in said trough at predetermined spaced points, longitudinally sealing the edges of the trough around the articles to form a tube, partially bunchng the tube from top to bottom between the articles therein, transversely bunchng the tube to a predetermined width between the articles, pressing the tube at said bunched points from top to bottom to seal the tube and cutting the tube at said seals.

26. The method of packaging articles in a continuous web of wrapping material which comprises continuously drawing wrapping material from a supply, forming said wrapping material into a horizontal trough, gripping and supporting the edges of the trough, placing articles to be wrapped in said trough at predetermined spaced points, converging the edges of the trough, longitudinally sealing the edges of the trough around the articles to form a tube, partially bunchng the tube from top to bottom midway between the articles therein, transversely bunchng the tube to a predetermined width midway between the articles, pressing the tube at said bunched points from top to oottom to seal the tube, and cutting the tube at said sea s.

27. In a package apparatus, means for supporting a supply of wrapping material, means for shaping and feeding the wrapping material to form an article-receiving trough, means for engaging with and continuously advancing the trough along a path, means positioned along the path of the trough for supporting articles placed into the trough at spaced intervals, means for sealing the edges of the trough to form a tube around articles placed therein, means for continuously advancing the tube and articles disposed therein, means for gathering the tube between the articles therein concomitantly with the tube advancement, means in alignment and operative concomitantly with said gathering means for bunching and sealing the tube along a plane extending at an angle to said gathering means, and means for severing the bunched and sealed tube between the articles.

28. A method of packaging articles including the steps of drawing wrapping material from a supply, forming said wrapping material into a horizontal trough, placing articles to be wrapped into the trough a-t predetermined spaced intervals, converging the edges of the trough, sealing the longitudinal edges of the trough to form a tube about the articles placed therein, continuously :advancing the tube and articles disposed therein, bunching the tube between the articles along different planes concomitantly with the tube advancement, sealing the tube at the bunched portions, and cutting the tube at the bunched and sealed portions.

References Cited in the le of this patent UNITED STATES PATENTS 2,180,966 Salsberg Nov. 21, 1939 2,555,758 Noble et al. June 5, 1951 2,718,105 Ferguson etal Sept. 20, 1955 

